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Experimental and Numerical Investigation for Vertical Stress Increments of Model Piled Raft Foundation in Sandy Soil

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Iranian Journal of Science and Technology, Transactions of Civil Engineering Aims and scope Submit manuscript

Abstract

Piled raft foundations have become a prominent foundation system in recent years as they combine bearing capacities of piles and raft. For this reason, comprehensive analytical, numerical and experimental studies have been carried out for reliable and economic design of piled raft foundations. In this study, vertical stress increments were mainly investigated experimentally and numerically. In the experimental study, model composite (steel and concrete) piles with a diameter of 20 mm and lengths of 200 and 300 mm were used. The raft was made of steel plate with plan dimensions of 160 × 160 mm and a thickness of 6 mm. The pressure gauges were placed at 2.5D, 5D and 7.5D intervals axially below center of model piled raft in the sand. The tests were carried out at different relative densities with the model piled raft. After model tests, numerical analyses were carried out with the FEM-based software ABAQUS, and the results were compared with the experimental results. From the tests results, it is determined that the piled raft foundations transfer loads to the deep layers with the help of piles, and the vertical stress increment reduces downward from the end of the piles. However, it is seen that the increase in relative density decreases the vertical stress increments in sand for same load. Some design parameters are suggested for use in foundation engineering applications.

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Abbreviations

A :

Numerical analysis

B :

Width of model raft foundation

C c :

Curvature coefficient

C u :

Uniformity coefficient

D :

Pile diameter

D r :

Relative density

D 10 :

Effective diameter

e :

Void ratio

E :

Modulus of elasticity

G s :

Grain specific gravity

L :

Pile length

LVDT:

Linear variable differential transformers

SW:

Well-graded sand

Q PR :

Bearing capacity of piled raft

S opt :

Optimum pile spacing

S/D :

Ratio of distance between piles to pile diameter

T :

Experimental test

\(\phi\) :

Internal friction angle

\(\gamma\) :

Unit weight

\(\rho_{{\text{d}}}\) :

Dry density

υ :

Poisson ratio

\(\psi\) :

Dilatancy angle

References

  • ASTM (2006) Standard test methods for specific gravity of soil solids by water pycnometer. ASTM D854-14. ASTM International, West Conshohocken

  • ASTM (2011) Standard test method for direct shear test of soils under consolidated drained conditions. ASTM D3080M-11. ASTM International, West Conshohocken

  • ASTM (2016a) Standard test methods for maximum index density and unit weight of soils using a vibratory table. ASTM D4253-16. ASTM International, West Conshohocken

  • ASTM (2016b) Standard test methods for minimum index density and unit weight of soils and calculation of relative density. ASTM D4254-16. ASTM International, West Conshohocken

  • ASTM (2017) Standard test methods for particle-size distribution (gradation) of soils using sieve analysis. ASTM D-6913. ASTM International, West Conshohocken

  • Ateş B (2019) Investigation of behavior of piled raft foundations at sandy soil by experimental and numerical methods. Ph.D. Thesis, Karadeniz Technical University, the Graduate School of Natural and Applied Sciences, Trabzon, pp 99–109

  • Bajad SP, Sahu RB (2008) An experimental study on the behaviour of vertically loaded piled raft on soft clay. The 12th International Conference of International Association for Computer Methods and Advances in Geomechanics (IACMAG), India, pp 84–91

  • Briaud JL, Jeanjean P (1994) Load settlement curve method for spread footings on sand. Vertical and horizontal deformations of foundations and embankments. ASCE 2:1774–1804

    Google Scholar 

  • Burland JB (1995) Piles as settlement reducers. Keynote address, 18th Italian congress on soil mechanics. Pavia, Italy, pp 21–34

    Google Scholar 

  • Burland JB, Broms BB, DeMello V (1977) Behavior of foundations and structures. Proceeding 9th International Conference on Soil Mechanics and Foundation Engineering, Tokyo, pp 495–546

  • Cao XD, Wong IH, Chang MF (2004) Behavior of model rafts resting on pile-reinforced sand. J Geotech Geoenviron Eng 130(2):129–138

    Article  Google Scholar 

  • Clancy P, Randolph MF (1993) An approximate analysis procedure for piled raft foundations. Int J Numer Anal Meth Geomech 17:849–869

    Article  Google Scholar 

  • Conte G, Mandolini A, Randolph MF (2003) Centrifuge modeling to investigate the performance of piled rafts. In: Van Impe WF (ed) Proc 4th int geotechnical seminar on deep foundations on bored and auger piles. Millpress, Rotterdam

    Google Scholar 

  • Cooke RW (1986) Piled raft foundations on stiff clays. A contribution to design philosophy. Géotechnique 36(2):169–203

    Article  Google Scholar 

  • Davis E, Poulos H (1972) The analysis of pile raft systems. Aust Geomech J 1(62):21–27

    Google Scholar 

  • Debeer EE (1970) Experimental determination of the shape factors and the bearing capacity factors of sand. Geotechnique 20(4):387–411

    Article  Google Scholar 

  • Dutte TT and Saride S (2015) Effect of confining pressure, relative density and shear strain on the poisson’s ratio of clean sand. 50th Indian Geotechnical Conference.

  • Fellenius BH (1989) Tangent modulus of piles determined from strain data. The ASCE Geotechnical Engineering Division Foundation Congress, vol 1, pp 500–510

  • Fellenius BH (2002) Determining the resistance distribution in piles. Geotechnical News 20(2):35–38

  • Fellenius BH (2004) Unified design of piled foundations with emphasis on settlement. In: Proceedings of the Geo-Institute Geo-TRANS Conference, Los Angeles, pp 253–275

  • Fioravante V, Giretti D (2010) Contact versus noncontact piled raft foundations. Can Geotech J 47(11):1271–1287

    Article  Google Scholar 

  • Geddes J (1966) Stresses in foundation soils due to vertical subsurface loading. Geotechnique 16(13):231–255

    Article  Google Scholar 

  • Giretti D (2010) Modeling of piled raft foundations in sand. Ph.D. Thesis. University of Ferrara

  • Gök S (2007) Design of piled raft foundation. Ph.D. Thesis, İstanbul Technical University, the Graduate School of Natural and Applied Sciences, İstanbul

  • Horikoshi K, Randolph MF (1996) Centrifuge modeling of piled raft foundations on clay. Geotechnique 46(4):741–752

    Article  Google Scholar 

  • Horikoshi K, Randolph MA (1998) Contribution to optimum design of piled rafts. Geotechnique 3(48):301–317

    Article  Google Scholar 

  • Huang M, Liang FY, Li Z (2007) Proceedings of the International Workshop on Recent Advances of Deep Foundations, Yokosuka, Japan. Taylor & Francis Group, London, pp 115–124

  • Kim SR, Chung SG, Fellenius BH (2011) Distribution of residual load and true shaft resistance for a driven instrumented test pile. Can Geotech J 48(4):583–598

    Article  Google Scholar 

  • Krasınski A, Kusio T (2015) Pile model tests using strain gauge technology. Stud Geotech Mech 37(3):49–52

    Article  Google Scholar 

  • Krasınski A, Wiszniewski M (2017) Static load test on instrumented pile-field data and numerical simulations. Stud Geotech Mech. https://doi.org/10.1515/sgem-2017-0026

    Article  Google Scholar 

  • Liang FY, Chen LZ, Shi XG (2003) Numerical analysis of composite piled raft with cushion subjected to vertical load. Comput Geotech 30(6):443–453

    Article  Google Scholar 

  • Liang FY, Li J, Chen LZ (2006) Optimization of composite piled raft foundation with varied rigidity of cushion. GeoShanghai International Conference, pp 29–34. https://doi.org/10.1061/40865(197)3

  • Mindlin RD (1936) Force at a Point in the interior of a semi-infinite solid. Physic 8:195

    MATH  Google Scholar 

  • NAVFAC (1984)  Foundations and Earth Structures. Department of the Navy Facilities Engineering Command, NAVFAC DM-7.2, Alexandria

  • Nguyen DDC, Jo SB, Kim DS (2013) Design method of piled-raft foundations under vertical load considering interaction effects. Comput Geotech 47:16–27

    Article  Google Scholar 

  • Poulos HG (1991) Analysis of piled strip foundations. In: Computer methods & advances in geomechanics, Balkema, Rotterdam, vol 1, pp 183–191

  • Poulos HG (2001) Piled raft foundations: design and applications. Geotechnique 2(51):95–113

    Article  Google Scholar 

  • Poulos HG (2002) Simplified design procedure for piled raft foundations. International Deep Foundations Congress, Orlando, vol 1, pp 441–458. https://doi.org/10.1061/40601(256)32  

  • Poulos HG, Davis EH (1980) Pile foundation analysis and design. Wiley, New York

    Google Scholar 

  • Randolph MF (1994) Design methods for pile groups and piled rafts. Thirteenth International Conference on Soil Mechanics and Foundation Engineering, New Delhi, vol 5, pp 61–82

  • Randolph M, Jamiolkowski M, Zdravkovic L (2004) Load carrying capacity of foundations. Proceedings of the Skempton Memorial Conference, London, pp 207–240

  • Rodriguez Rincon E, Cunha RP, Caicedo Hormaza B (2019) Analysis of settlements in Piled Raft Systems founded in soft soil under consolidation process. Can Geotech J 57(4):12

    Google Scholar 

  • Schanz T, Veermer PA (1996) Angles of friction and dilatancy of sand. Geotechnique 46(1):145–151

    Article  Google Scholar 

  • Trautmann CH, Kulhawy FH (1998) Uplift load-displacement behavior of spread foundations. J Geotech Eng ASCE 114(2):168–183

    Article  Google Scholar 

  • Vakili R (2015) Load sharing mechanism of piled-raft foundation in sand. PhD Thesis, Concordia University, Montreal.

  • Viggiani C (1998) Pile groups and piled rafts behavior. 3rd Int. Geot. Seminar on Deep Foundations on Bored and Auger Piles, Ghent, pp 77–94 

  • Viggiani C (2001) Analysis and design of piled foundations. 1st Arrigo Croce Lecture, RivistaItaliana di Geotecnica, vol 1, pp 47–75

  • Wong IH, Chang MF, Cao XD (2000) Raft foundations with disconnected settlement-reducing piles. Design applications of raft foundations, London, pp 469–486. https://doi.org/10.1680/daorf.27657.0017

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Authors and Affiliations

  1. Department of Civil Engineering, Karadeniz Technical University, 61080, Trabzon, Turkey

    Bayram Ateş & Erol Şadoglu

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  1. Bayram Ateş
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  2. Erol Şadoglu
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Correspondence to Bayram Ateş.

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Ateş, B., Şadoglu, E. Experimental and Numerical Investigation for Vertical Stress Increments of Model Piled Raft Foundation in Sandy Soil. Iran J Sci Technol Trans Civ Eng 46, 309–326 (2022). https://doi.org/10.1007/s40996-021-00618-7

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